Introduction. RSS-Compability-US-TI-en-10 Version 1.0

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1 Technical Information Rapid Shutdown of PV Systems on Buildings (NEC 2014) with SMA Residential Inverters, SMA Rapid Shutdown Box (RSB) and SMA Rapid Shutdown Controller (RSC) Introduction The purpose of this note is as follows: to explain and identify acceptable combinations of SMA Residential Inverters and the SMA Rapid Shutdown Box (RSB). to identify recommended types of wire/cable for Rapid Shutdown Controller (RSC) connection, multi-tap connectors for the inverters SBx.x-1SP-US-40 (Sunny Boy x.x-us), and sealing gaskets for raintight conduit fittings and cable glands. This document is intended for use by SMA customers. The Background is as follows: NEC specifies a requirement for rapid shutdown of PV systems installed onbuildings SMA supplies a UL listed device meeting NEC RSS-Compability-US-TI-en-10 Version 1.0 AMERICAN ENGLISH

2 1 Applicable Products SMA Solar Technology America LLC 1 Applicable Products SMA Inverters SBx.x-1SP-US-40 SB xx00tl-us-22 SMA Rapid Shutdown System RSB-2S-US-10 RSC-1X-US-10 2 SMA Rapid Shutdown Controller Wiring/Cabling The SMA Rapid Shutdown System consists of a Rapid Shutdown Box (RSB) and a Rapid Shutdown Controller (RSC). As shown and specified in the Installation Manual, RSBs and RSCs are connected with control wires, and multiple RSBs can be controlled with a single RSC. Below are the specifications and examples of recommended wire types and sources. Requirements for Control Wires 18 AWG to 16 AWG copper conductors Solid wire, stranded wire or finely stranded wire. When using finely stranded wire, bootlace ferrules must be used. Examples Version RSB channels Maximum channel Short circuit Enclosure Rating current per channel [adc] RSB-2S-US NEMA 4X Tray cables for exposed run (TC-ER) Where 600V rated cable is required: Belden 28335A Multi-Conductor 600V Type TC-ER Cable or similar In conduit with PV output conductors (600V rated) TFFN individual copper conductors sizes AWG 18 16, 600 V or 600 Vdc tray cable. Verify conduit fill. Belden 28335A Multi-Conductor 600V Type TC-ER Cable or similar Diagram from installation manual 2 RSS-Compability-US-TI-en-10 Technical Information

3 SMA Solar Technology America LLC 3 Multi-tap Connector use with SMA Rapid Shutdown System and 3 Multi-tap Connector use with SMA Rapid Shutdown System and SBx.x-1SP-US-40 Inverters The SMA Rapid Shutdown System consists of one or more Rapid Shutdown Boxes (RSB) and one Rapid Shutdown Controller (RSC). The RSB is a two channel device. Each channel is capable of operating at 20 Amps of PV current and has a Maximum Circuit Current rating of 36 Amps. In many cases, three or more strings may be connected to each Rapid Shutdown Box with each channel operating at 16 Amps or more. See the installation manual for more details. For example For a three string installation of typical PV modules with approximately 8.5 Amps Imp and 9.5 Amps Isc, an installer can connect two strings to RSB Channel A input giving a total combined Imp of 17 Amps and a total Maximum Circuit Current of 23.8 Amps. Channel B would be connected to a single string of PV modules with a total Imp of 8.5 Amps and a total Maximum Circuit Current of 10.6 Amps. For the SBx.x-1SP-US-40 inverters, each inverter can be wired with Up to 3 independent MPP inputs (A), (B), and (C) operating at up to 10 Amps and rated at 18 Amps Maximum Circuit Current or 2 combined MPP inputs and a single MPP input (A B) and (C) inputs A and B operating in parallel at up to 20 Amps and rated at 36 Amps Maximum Circuit Current. This configuration has two strings on input (A B) and one on input (C) per the diagram below. Three wire, insulated, multi-tap connectors are used to combine inputs A and B on the inverter. Reference Diagram Important A/B Strings need to have the same quantity of modules in series. 3-Wire Connectors needed to transition from one conductor to two conductors are not provided by SMA. Technical Information RSS-Compability-US-TI-en-10 3

4 4 Requirements for Insulated Multi-Tap Connector SMA Solar Technology America LLC 4 Requirements for Insulated Multi-Tap Connector 600 V, 90 C, rated for copper conductors Compatible wire range 10 AWG to 6 AWG Examples ILSCO Nimbus PBTS Series Part # PBTS-3-4 Polaris IPL Series Part # IPL 4-3 or IPL4-3A Polaris IPLM Series Part # IPLM 4-3 or IPLM 1/0-3 Polaris Grey Series Part # IPLG6-3 or IPLG1-3 Burndy UNITAP Series Part # BIBS43 5 SMA Rapid Shutdown System Sealing Gaskets for Raintight Conduit Fittings and Cable Glands The SMA Rapid Shutdown System consists of one or more Rapid Shutdown Boxes (RSB) and one Rapid Shutdown Controller (RSC). As shown and specified in the Installation Manual, the RSB and RSC require listed raintight or liquidtight conduit fittings to attach the conduits to the enclosure. The RSC ships with the appropriate raintight RSC knockout to 3 4 NPT adapter. Installers must procure conduit fittings for the RSB and RSC. SMA recommends using fittings with flat, pliable, thick rubber sealing gaskets per the diagrams below. Thickness should be of approximately 0.1 inch (approximately 7 64 inch). SMA recommends against using fittings with thinner, harder sealing gaskets, typically yellow or green colored. These types of gaskets may not make reliable seals for this application. Gasket is approximately inch ( 5 64 inch) thick or less. SMA recommends against and does not accept using fittings with round cross section, o-ring type sealing gaskets as these types of seals are not reliable for this application. Recommended Not Recommended Not Acceptable 0.1 inch flat gasket inch flat gasket O-ring 4 RSS-Compability-US-TI-en-10 Technical Information

5 SMA Solar Technology America LLC 6 Configuration Recommendations and Reference Diagrams 6 Configuration Recommendations and Reference Diagrams 6.1 Important Notes If PV subarrays on a roof are separated by distances greater than defined in 2014 NEC , then at least one RSB will be required per subarray. Two strings can be directly connected to one channel of the SMA RSB if the total module short circuit current is equal to or less than 36A Isc. Each channel has two string inputs. Unused channels should be capped. MC4 caps are supplied with the RSB. Per NEC 690.9(A)(b) fuses are not required for two strings. Always consult module manufacturers installation instructions. Two parallel strings per one SMA MPP input may cause power clipping at full sun conditions. The significance of this occurrence is inverter, module, and site dependent. 6.2 Reference Diagrams SMA Sunny Boy Part numbers SBx.x-1SP-US-40 Installed Strings RSB Qty. MPP1 MPP2 MPP3 RSB-1 CH 1 RSB-1 CH Technical Information RSS-Compability-US-TI-en-10 5

6 6 Configuration Recommendations and Reference Diagrams SMA Solar Technology America LLC SMA Sunny Boy Part numbers SBx.x-1SP-US-40 Installed Strings RSB Qty. MPP1 MPP2 MPP3 RSB-1 CH 1 RSB-1 CH Important A/B Strings need to have the same quantity of modules in series. 3-Wire Connectors needed to transition from one conductor to two conductors are not provided by SMA. 6 RSS-Compability-US-TI-en-10 Technical Information

7 SMA Solar Technology America LLC 6 Configuration Recommendations and Reference Diagrams SMA Sunny Boy Part numbers SBx.x-1SP-US-40 Installed Strings RSB Qty. MPP1 MPP2 MPP3 RSB-1 CH 1 RSB-1 CH 2 RSB-2 CH Technical Information RSS-Compability-US-TI-en-10 7

8 6 Configuration Recommendations and Reference Diagrams SMA Solar Technology America LLC SMA Sunny Boy Part numbers SB xx00tl-us-22 Installed Strings RSB Qty. MPP1 MPP2 RSB-1 CH 1 RSB-1 CH RSS-Compability-US-TI-en-10 Technical Information

9 SMA Solar Technology America LLC 6 Configuration Recommendations and Reference Diagrams SMA Sunny Boy Part numbers SB xx00tl-us-22 Installed Strings RSB Qty. MPP1 MPP2 RSB-1 CH 1 RSB-1 CH Technical Information RSS-Compability-US-TI-en-10 9

10 6 Configuration Recommendations and Reference Diagrams SMA Solar Technology America LLC SMA Sunny Boy Part numbers SB xx00tl-us-22 Installed Strings RSB Qty. MPP1 MPP2 RSB-1 CH 1 RSB-1 CH RSS-Compability-US-TI-en-10 Technical Information